1. Field of the Invention
The present invention relates to a positioning structure for heat dissipating fins and in particular, a high-density buckling mechanism for a stack of heat dissipating fins comprising a plurality of metal plates.
2. Description of the Prior Art
As computer technology advances to deep sub-micron age, the dimension of microchips dramatically shrinks and the speed of these chips largely increases. This causes a heat problem when operating such high-density microchips. To dissipate the heat generated by the operating microchips and to avoid the chips from burning down, heat dissipating fins having large heat: dissipating area are typically combined with the microchips. Generally, according to their fabrication method, there are three types of them: aluminum extrusion type, pressing molding type, and folded stack type. The aluminum extrusion type and pressing molding type heat dissipating fins are superseding folded stack type heat dissipating fins these days since the former provides limited heat dissipating area due to fabrication ability. The later provides higher packing density and thus has higher heat dissipating performance.
FIG. 1 illustrates a typical view of a prior art folded stack type heat dissipating fin structure. The prior art folded stack type heat dissipating fin structure 10a comprises a plurality of metal plates 11a each of which is formed by means of conventional mechanical pressing method and has similar size. The metal plate 11a is made of metal materials with high thermal conductivity such as copper or aluminum. Typically, the metal plate 11a is shaped into a U-shape or approximate L shape. The metal plate 11a comprises a main body 12a connected with an upper folded side and lower folded side 13a arranged in a parallel manner. The metal plates 11a are connected with a heat dissipating substrate 20a by soldering the lower folded side 13a with the surface of the substrate 20a. The substrate 20a is typically made of high thermal conductive metal materials such as copper or aluminum.
As illustrated in FIG. 1, to position the metal plates 11a, there are provided protruding portions 14a and corresponding recess portions 15a on each of the upper and lower folded sides 13a. The metal plates 11a are stacked in position by engaging the protruding portions 14a with the corresponding recess portions 15a. However, such prior art positioning mechanism provides poor combination. Sometimes, metal plates 11a fall off due to collision.
FIG. 2 shows another prior art folded stack type heat dissipating fin structure, the heat dissipating fins 30a comprises a plurality of metal plates 31a having at least one pair of buckling pieces 32a disposed at two opposite sides of each of the metal plates 31a. Each of the buckling pieces 32a defines a locking opening thereof. With such configuration, the metal plates 31a are stacked in approximately equal spacing for the sake of convection. An extending heat conducting strip 33a is combined at the lower side of each of the, metal plates 31a. When assembling, the extending heat conducting strip. 33a provides more heat dissipating area.
Unfortunately, the above-mentioned prior art cannot provide firmly joint between two metal plates. Accordingly, there is a strong need for an improved positioning structure for heat dissipating fins which are simplified and have good reliability.
The main objective of the invention is to provide an improved positioning structure for heat dissipating fins to solve the above-mentioned problems.
In accordance with the present invention, a positioning structure for heat dissipating fins is provided. The heat dissipating fins is comprised of multiple metal plates, each of which comprising a main body, and a folded side portion connected to one or two sides of the main body. The positioning structure is disposed on each of the metal plates. The positioning structure comprises a protrusion located on the main body of the metal plate, an aperture being formed on the main body, the protrusion formed in the aperture; and a resilient snapping piece located on the folded side portion, the snapping piece corresponding to the protrusion and defining a buckling opening therein, the buckling opening being connected to a front opening having a width normally smaller than the width of the protrusion.